The present invention relates to the technical area of packaging, and more precisely the area of packaging a fluid product, in general liquid but which can also be in paste or gel form. The packaged product is intended to be kept germ-free without addition of a preservative, to be protected from oxidation, or to be sheltered from all external pollution, although in contact with the air, and also intended to be dispensed in unit doses by means of a manual pump.
More particularly, the object of the invention is a device for packaging and dispensing a product in unit doses. The device includes a container that is able to contain the product to be dispensed in unit doses by means of a manual pump, of the type without an air intake, which is mounted on the container while tightly sealing an opening in the container, for example, the open neck of a flask.
Packaging and dispensing devices of conventional structure are known to comprise a container on which is fitted a manual pump for dispensing the product contained in the container. The pump generally includes a plunger which allows a piston to be moved by simple finger pressure in a pumping chamber, the volume of which determines the dose of the product to be dispensed. A first valve allows the chamber to be isolated from the internal volume of the container when the product is expelled from the chamber through a second valve. As a result of the movement of the piston caused by pressure on the plunger, the second valve allows the chamber to be isolated from the outside. When this chamber is filled via the first valve with a dose of the product coming from inside of the container, the dose is drawn into the chamber by the return of the piston towards its initial position. The dose of the product rests on a stop forming part of the pump body enclosing the pumping chamber, wherein the piston is caused to slide by elastic return means.
Thus, each time the piston returns to its starting position, reached by the effect of elastic return means, such as a spring, a dose of product is drawn into the pump chamber.
This suction of the product causes a partial vacuum inside the container.
For this reason, it is necessary to admit air from the outside into the container. This admission of air is generally provided through the pump.
The major disadvantage of this type of device lies in the fact that the admission of outside air to the interior of the container does not allow the product contained in the container to be kept sterile, to be protected from oxidation, or from all external pollution.
To remedy this disadvantage, different types of devices are proposed. For example, a device that comprises a pump without an air intake and a deformable container which contains the product to be packaged and dispensed by the pump has been proposed. The deformable container is an internal container around which a rigid external container is provided to ensure the mechanical protection of the deformable internal container. Each time a dose of the product is expelled from the deformable container, the partial vacuum created in the container causes contraction of the deformable container. In order for a device with a double container to function, it is necessary that the deformable internal container is able to retract.
For this reason, it is necessary to allow outside air to enter the space enclosed between the deformable internal container and the rigid external container.
This air intake can be provided near the neck of the container or at a passage at the bottom of the rigid container.
Further devices include an outside air intake circuit through the pump, which is fitted with a closing system which allows outside air to enter the space between the two containers when the pump is actuated. The closing system prevents vapors from the product, which have passed through the wall of the deformable container and are present in the space between the two containers, from escaping from this space to the outside when the pump is not being actuated.
A disadvantage of this type of device lies in the fact that it requires the use of a pumps including an air intake circuit, distinct from the product outlet circuit, and a closing system for the air intake circuit. Such a pump has a complex structure comprising a large number of parts that are intricate and difficult to fabricate.
Another disadvantage lies in the fact that when the deformable container has begun to retract it tends, through its own elasticity, to return to its starting position, thereby creating a partial vacuum within the product it encloses.
A consequence of this partial vacuum, principally when the product is a liquid or a fluid, and in particular a paste or a gel, is the appearance of a cavitation phenomenon leading to the formation of bubbles which impair the precision of the dosage.
Another type of a known device comprises a conventional container with a single rigid wall on which is fitted a pump with an air intake circuit. The air intake circuit includes a filter for sterilizing or absorbing the oxygen from the air, for keeping the product sterile, for protecting it from oxidation and for protecting the product from any external pollution.
In such a device, for example, FR-A-2 669 379, the outside air enters the container to compensate for the partial vacuum created by each action on the pump . This causes a dose of the product to be released such that it is filtered in a sterile manner.
The sterility of the product in the container is not, therefore, affected by contact with air coming from the outside. This is advantageous for the packaging and dispensing of pharmaceutical products.
The major disadvantage of this type of packaging device is the need to use a special pump, including a filter. The addition of the filter to the pump is a delicate and onerous operation, as it requires substantial structural modification to known pumps.
Packaging devices of this last type have been described, notably in FR-A-2 669 379, but, to the knowledge of the Applicant, none has been commercialized up to now.
A first objective of the invention is to propose a device for packaging and dispensing a product with a conventional container, a manual pump and a filter, which allows the use of standard dosing pumps that are available at low cost on the market.
Another objective of the invention is to propose such a device in which the creation of a partial vacuum inside a generally liquid product, paste or gel, is avoided, in order not to distort the dosage.
More generally, the objective of the invention is to remedy the disadvantages of similar devices representing the state of the art, and to propose such a device which meets the various practical demands better than known devices.
A device for packaging and dispensing a fluid product, which is generally liquid but may be, a paste or a gel. The packaging and dispensing device includes a container with a single rigid wall for containing the product to be packaged and dispensed, a manual pump mounted on the container for dispensing the product in unit doses, and a filter for filtering outside air entering the container when the pump is actuated. The pump has no air intake in the container and the filter is arranged in an air intake passage provided in the base of the container, which is injection-molded in a synthetic material.
Outside air can pass through the air intake passage and the filter, which is preferably sterile, and can compensate the partial vacuum created in the container when the user operates the pump.
The container is advantageously formed of two parts, a neck and a body. The neck has an open mouth on which the pump is mounted in a tightly sealing manner. The body with a base including the air intake passage which accommodates the filter, the two parts being injection-molded separately and then assembled in a sealed manner.
In a first, advantageously simple embodiment, the filter is mounted in a rigid sheath, preferably made of plastic and closely fitted to the filter. The outer shape of the sheath matches the part of the air intake passage in which the sheath is fixed by any appropriate means, such as pressure fitting, ultrasonic welding or snap-fitting.
Since sterile filters allow both gases and liquids to pass, a filter made of a hydrophobic filtering material will advantageously be chosen when the product to be packaged and dispensed is of an aqueous nature. A filter made of an absorbent filtering material will be chosen when the product for packaging and dispensing is of a non-aqueous nature.
Thus, when the product for packaging and dispensing is of an aqueous nature, the hydrophobic filter admits outside air but repels the product, which cannot escape to the outside thereby avoiding any risk of leakage. When the product for packaging and dispensing is of a non-aqueous nature, the absorbent filter admits outside air but repels the product which cannot escape to the outside.
In a variant, the device comprises a valve arranged between the filter and the internal space of the container for preventing any escape of the product contained in the container through the air intake passage and to avoid any contact between the product and the filter.
Advantageously, the valve is elastically deformable and cooperates with a conical seat, on the end, which is turned towards the inside of the container of a shaft formed integral with the base and defining the air intake passage in which the filter is retained. Such an elastic valve can efficiently oppose any escape of product to the outside of the container through the air intake passage, while admitting outside air by flexing elastically towards the inside of the container under the effect of the suction of outside air during the phase of pumping a dose of product from the internal space of the container.
Advantageously, the elastic valve is retained by a plug on the end of the shaft facing towards the inside of the container. In this case, the air intake passage may include grooves provided in the conical seat and the wall of an orifice in which the plug fixing the valve on the shaft is retained.
In these different variants, it is always advantageous for the filter, with its sheath if applicable, to be mounted in a conical central part of a shaft formed in one piece with the base of the container.
If it is desired to facilitate the injection-molding of the body of the container, starting from a central point in its base, it is advantageous that the conical central part of the shaft be closed towards the outside of the container by a base in which a hole for the air intake passage is provided eccentrically.
In another variant, which allows the maximum of the product contained in the container to be dispensed, the air intake passage opens to the inside of the container in the central part of a conical base of the container. The base widens towards the inside of the container permitting an optimum emptying of the container.
As the body of the container, like its neck, if applicable, is made of plastic using injection techniques, a perfect geometry can be advantageously obtained for the part of the air intake passage in which the filter is housed, for the conical seat on which the elastic valve is fitted and for other structural characteristics such as the grooves in the air intake passage.
With the objective of simplifying the manufacture of the filter, especially when it is sterile, commercial filters normally used in conjunction with a syringe and a needle can be used. These commercial filters are housed in a plastic sheath including a conical female part for assembling with the conical male outlet of the syringe and a conical male part for assembling with the conical female part of the needle. For this reason, it is advantageously proposed that the air intake passage includes a female conical part in which the male conical part of the filter sheath is assembled, if applicable, by a simple snap fit.
Other characteristics and advantages of the invention can be seen from the description given below, with reference to the attached drawings, which show, by way of non-limiting examples, embodiments of the construction and use of the object of the invention.